Hitchcocks Forum

Hi Guys

I will be building Redditch based engine. i have 2 crank. one clipper 350 and bullet 350 one.
what are crank weight for bullet. heavier crank means better thump sound ?

anyone history of crank weight used Thanks

Regards
ET

someone put these in other forum benefits of heavier crank

" The reasons for heavy crank are many but some of them are:

1. Frequency of changing gears is less
2. Can easily chug at less than 20 KMPH in 4th gear
3. Engine revvs less thereby throttling less and engine wear and tear reduces
4. Better torque from standstill(Awesome Pulling power can literally be felt on upward slopes) "

If you are building a traditional type 4-stroke trials engine you want to fit heavy flywheels, Royal Enfield actually used the wheels from the 500 Bullet in the 350 Works Replica. (I have one and the crank and rod weighs a not inconsiderable 23lbs.) Flywheel effect helps the engine reliably generate sparks at low revs if you have a magneto and ensures good low speed traction, good for downhill or loose surfaces. Reduced wear and tear is not an issue for competition machines, winning is everything! I can't remember what engine you are using, if it is the early (pre-1955) type the 500 wheels will not fit so you have to use the 350 type. Polishing the flywheels is also done to reduce drag from oil and improve bottom end performance, I have a set of wheels here which have been done like this. Having said all that some of Enfield's own Works Team actually preferred light flywheels as the Enfield engine likes to rev if conditions need it, for instance on long hills. Don Morley's book "Classic British 4 stroke Trials Bikes" has a very good section on Enfields, he owned many ex-Works machines and explains all their secrets. Get a copy if you are serious in building a Trials machine in the classic style!

REgards, Mark